Referring to FIG. 1, the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard (802.11) defines several mechanisms for wireless devices, or nodes, to communicate. One frequently used mechanism is a Basic Service Set (BSS) 10, also known as “infrastructure mode”. In the BSS 10, an end node (referred to as a station (STA)) communicates with an Access Point (AP). The AP is typically connected to a Wide Area Network (WAN) (not shown) that includes an Internet network.
Two additional mechanisms are defined in IEEE 802.11 that enable devices to communicate on a peer-to-peer basis. An Independent Basic Service Set (IBSS) 12 is alternatively referred to as an “ad hoc” mode and allows two STAs to communicate directly with each other. A Wireless Distribution Services (WDS) network 14 allows two APs to communicate directly with each other.
In the IBSS 12, nodes seek out other nodes that are members of a specific service set identified by Service Set Identifiers (SSIDs). The STAs in the IBSS network 12 seek out other nodes by listening for beacons and using a Timing Synchronization Function (TSF) value to arbitrate a Distributed Coordination Function (DCF) within the IBSS network 12. When a node finds other nodes on a particular wireless channel (a pre-defined, standardized frequency band), it will select that channel and join the IBSS network 12. If a node does not locate any other nodes with the desired SSID, it will select a wireless channel and start its own IBSS network 12. The nodes use 3-address 802.11 frames for operating within the IBSS 12. In a WDS 14, two or more APs are configured to bridge among themselves using address 0802.11 frames. The WDS 14 has no concept of a BSS 10 and all frames are forwarded point-to-point.
Either one of these two wireless frameworks can be used as the starting point, or baseline functionality, for defining a mesh discovery protocol. Both 3-address and 4-address data frames can support mesh discovery functionality. However, none of the protocols currently used for the BSS 10, IBSS 12, or WDS 14 provide the functionality required for effectively supporting dynamically changing mesh networks.
The present invention addresses this and other problems associated with the prior art.